Transcript File
SCIENTIFIC METHOD • What is the Scientific Method? • It is a process that is used to find answers to questions about the world around us • What is data? • Information gathered during an experiment • What is an hypothesis? • Is an educated guess based on observations and your knowledge of the topic STEP 1: IDENTIFY THE PROBLEM/ASK A QUESTION* • What do you want to know or explain? Use observations you have made to write a question that addresses the problem or topic you want to investigate STEP 2: FORM A HYPOTHESIS* • What do you think will happen? Predict the answer to your question or the outcome of the experiment STEP 3: CREATE AN EXPERIMENT* • How will you test your hypothesis? Develop a procedure for a reliable experiment and address safety rules STEP 4: PERFORM AN EXPERIMENT* • Follow the steps in your procedure to perform your experiment. Record data and observations in detail STEP 5: ANALYZE THE DATA* • Is the data reliable? Does your data and observations from the experiment support your hypothesis? IS THE HYPOTHESIS TRUE (PARTIAL)? • YES Step Results* 6A: Communicate the • Write a conclusion that summarizes the important parts of your experiment and the results IS THE HYPOTHESIS FALSE? • Is your data inaccurate or the experiment flawed? Or is your question still unanswered? • Step 6B: Modify the Experiment* • Look back to your hypothesis, consider changing it to reflect your recent findings. Or, rewrite your procedure to address the flaws in the original experiment PARTS OF AN EXPERIMENT • What are the two variables in an experiment? • Independent Variable • Dependent Variable INDEPENDENT VARIABLE • the variable that is changed or manipulated in an experiment DEPENDENT VARIABLE • What is being measured, what changes because of the independent variable EXPERIMENTAL GROUP • the factor being tested / the change in the experiment • You usually store your microwave popcorn in the kitchen cabinet, but you read an article that recommends storing it the refrigerator. You want to find out if microwave popcorn actually pops better if it is stored in the refrigerator. You have two bags of popcorn so you keep one in the cabinet and place the other in the refrigerator. The next day you pop each bag of popcorn for the same amount of time in the microwave. You measure the amount of popcorn that popped in each bag to see which bag produced more. • You just created an experiment to test whether storing the popcorn in the refrigerator makes it pop better. In this example, your experimental group is the bag of popcorn you placed in the refrigerator. An experimental group is the group that receives the variable being tested in an experiment. CONTROL GROUP? • the normal group, the base line • The normal group would be the bag of popcorn in the cabinet. GRAPHING • Y & X Axis Y X HOW DO YOU GRAPH A POINT? • Over and then up • X then Y • What axis is the Independent Variable on? • The X-axis • What axis is the Dependent Variable on? • The Y-axis MAPS READING MAPS LINES ON MAPS • Latitude • Horizontal lines on the globe. All lines running horizontal North and South of the equator • Equator is the 0 point latitude line. • Longitude • Vertical lines on the globe • Also called Meridians • The prime meridian passes through Greenwich, England. It is the 0 point of longitude TOPOGRAPHIC MAPS • Represents Earth’s 3 dimensional surfaces in 2 dimensions • This map is special because they show elevation • Elevation = height • On maps 0 elevation = ground is at sea level • High elevation = how high above sea level HOW TO SHOW ELEVATION • Elevation is shown by contour lines TOPOGRAPHIC MAP • Contour Interval: the difference in elevation between contour lines • Steepness of the elevation can be determined by the closeness of the contour lines. The closer the lines, the steeper the elevation. Igneous Rock Formation When magma hardens or lava cools. Intrusive: formed within the earth Extrusive: formed on the surface of the earth Destruction Weathering and Erosion - the removal of rock due to wind, water, ice or gravity. Sedimentary Rock Formation Sediment from weathering and erosion is deposited and then rock is formed from cementation. Destruction Under high pressure and heat Metamorphic Rock Formation Rocks are changed by heat or pressure. This is often when how magma is introduced to a body of rock. Destruction Metamorphic rocks are destroyed when they are heated up as magma. Weathering Weathering is when an object wears away or changes its appearance by long exposure to the air. 2 Types of Weathering Mechanical Chemical Mechanical Weathering A rock breaks down into smaller and smaller pieces but it doesn’t change it’s chemical composition 3 types: 1. Frost Wedging 2. Unloading & Exfoliation 3. Biological Activity Chemical Weathering Changes the chemical composition of rocks, turning it into a new compound. Happens when water mixes with minerals. Erosion A destructive natural force 4 main types Wind Water Ice Gravity Convection Convection currents occur in: The middle mantle Convection currents are caused by: The outer core heats up the magma in the in the mantle. Hot, less dense magma rises. It cools, and the cool, less dense magma sinks Types of Plate boundaries Convergent Boundaries Reverse Faults (Strong & Deep) Cause earthquakes Volcanoes occur at subduction zones Divergent Boundaries Normal Faults (Weak & Shallow) Ridges form Rifts cause seafloor spreading Transform Boundaries Strike-Slip Faults (Moderate & Shallow) Earthquakes occur Viscosity & Volcanoes What is Viscosity? Viscosity is how resistant a substance is to flowing. For example, honey is more viscous than water. Magma that is very viscous will explode, magma that is less viscous will flow. Types of Volcanoes Shield Volcanoes Broad shape, fluid lava, non-violent eruptions Cinder Cone Volcanoes Steep sides, short lifespans, eject lots of cinders Composite / Strato Volcanoes Huge, in Ring of Fire, produce lava & pyroclastic flow, can cause lahars Nebular Hypothesis • The solar system began by the collapse of an interstellar gas cloud called a nebula. • The collapsing cloud quickly becomes spherical in shape and flattens into a spinning disk • The cloud begins rotating faster & faster. • The large blob in the center became the sun. Smaller blobs in the outer regions became planets The (whole) Earth moves in 3 ways. The Earth: 1.Rotates (Rotation) 2.Orbits 3.Revolves (Revolution) The earth rotates on its axis. • Rotates = spins. • The earth makes 1 full rotation every 24 hours. The axis of the Earth is tilted at an angle of 23.5 degrees. The axis always points towards the North Star. • We have day and night because of the Earth’s rotation. The Earth also revolves around the sun in an elliptical orbit. The earth makes one full revolution around the sun every 365.25 days. 365 days = 1 year Kepler’s Three Laws of Planetary Motion (A Summary) 1. Each planet takes an elliptical path around the sun 2. Planets travel faster when they are close to the sun and slower when they are farther away from the sun 3. The amount of time needed for a planet to revolve around the sun is proportional to the the planet’s distance from the sun A B C What is Kepler’s first law? First law- Laws of ellipses Planet’s orbit around the sun in the shape of an ellipse. Second law: Law of equal areas What is Kepler’s second law? Planet’s revolve around the sun at varying speeds. Each planet revolves so that an imaginary line connecting it to the sun sweeps out over equal areas in equal time intervals. What is Kepler’s third law? Third law: Law of Harmonies There is a proportional relationship between a planet’s orbital period (length of year) and its distance to the sun. The further a planet is from the sun, the longer it’s orbital period will be. (T2=d2) Precession The direction the axis of a planet is pointing in will change, but the tilt will not change. This will change the stars near the pole but will not change the seasons (as long as the angle of the tilt, 23.5 in the case of Earth, stays the same) Precession is the phenomenon by which the axis of a spinning object “wobbles” when a torque is applied to it. Nutation Nutation happens when the axis of a planet starts to wobble (do the wobble!) The angle of the axis will change during nutation ½ degree one direction or the other Nutation happens over the course of 18 years Nutation is a direct result of the moon (or moons) of a planet Barycenter http://www.youtube.com/watch?v=_IHXj8k2jqc and http://www.y outube.com/watch?v=1iSR3Yw6FXo A barycenter is the point between two objects where they balance each other (For example, the middle balancing point on a scale). http://www.youtube.com/watch?v=uGBANgbRkws For example, the moon does not orbit the exact center of the Earth, but a point on a line between the Earth and the Moon approximately 1,710 km below the surface of the Earth, where their respective masses balance. This is the point at which the Earth and Moon orbit as they travel around the Sun There are 2 tides in any 24 hour period. Radiation The emission of energy from the sun as electromagnetic waves Types of Radiation: Gamma Ray X-Ray Ultraviolet Visible Light Infrared Microwave Radio wave The earth is made up of three different layers: ◦ Crust Oceanic Continental ◦ Mantle Upper Mantle Middle Mantle Lower Mantle ◦ Core Inner core Outer core Lithosphere - rigid outer layer ◦ Crust and upper mantle (rigid part)